I'm designing call tracking software so offline marketers can
determine the number of calls each of their print ads generate. Each
print ad will have a different phone number, and those phone numbers
will forward to the main business number.

The end user needs to be able to request from the system a new phone
number to place in a new ad. The system needs to provision the phone
number on demand.

I need answers or links to information for the following:
* How are phone numbers provisioned?
* What components need to be in place to let my software capture the
phone call and forward it to the business number?

HI...
-ID caller facility is provided by the service provider.
-in this no of the caller is forwarded to the called person & stored in his device.
-we can access that no from there.
-to do so we have to couple hardware with the software.
-using this software access the no and use that no as the KEY to the database.
-now we can search the address of the desired person with this phone no.

i am not clear with ur ques. if you can provide me some more info then
i can ans in a better way.